This invention relates generally to lighting equipment and more particularly concerns a fixture using light emitting diodes to simulate a neon light.
Neon lights are widely used in commercial applications as decorative enhancements, information communicators and back lights. For example, they are used to highlight architectural features or to display names, logos and the like.
Neon lights are generally chosen for their neon affect or glare which demands the viewer""s attention. This ability to draw attention outweighs the many drawbacks associated with neon lights. They are fragile, high voltage, energy consuming, monochromatic devices with inconsistent life patterns. They are labor intensive and require licensed tradesmen for installation and replacement. From a practical standpoint, any other type of lighting would be desirable if it could produce the attention demanding impact associated with neon.
It is, therefore, an object of this invention to provide a simulated neon light which is durable. Another object of this invention is to provide a simulated neon light which operates at low voltages. A further object of this invention is to provide a simulated neon light which conserves energy. It is also an object of this invention to provide a simulated neon light which is easy to install. Still another object of this invention is to provide a simulated neon light which is easy to maintain. An additional object of this invention is to provide a simulated neon light which is long lasting. Yet another object of this invention is to provide a simulated neon light which is non-monochromatic. A further object of this invention is to provide a simulated neon light which is inexpensive.
In accordance with the invention, a neon light is simulated using light emitting diodes as a light source. An elongated, translucent diffuser of circular cross-section is mated with an elongated opaque tubular housing of constant cross-section with a lengthwise slot. The diffuser is held in longitudinally aligned abutment against the edges of the housing slot to form a chamber between the housing and the diffuser from which light may only be emitted through the diffuser.
A plurality of light emitting diodes is aligned in a linear array in the chamber. The plurality of diodes is connected to an electrical power source for energizing the diodes. The light emitted from the diodes can only pass from the chamber into the wall of the diffuser along the slot and out of the wall of the diffuser outside of the housing. The refraction and reflection of light by the tubular diffuser produces a neon-like glow or glare with an appearance of substantially homogeneous light intensity across the exposed surface of the diffuser. The housing has a maximum width taken in a direction parallel to a plane traversing the slot which is not greater than the diameter of the diffuser, so that the housing is hidden behind the diffuser. The diffuser is preferably made of polyethylene, but any material having an index of refraction in a range of that of polyethylene can be used.
In an alternative embodiment, the diffuser has a lengthwise slot contiguous with the housing slot, so that the light from the diodes is refracted and reflected over more than a 180 degree arc of the diffuser. However, the diodes do not physically penetrate within the circumference of the diffuser.
This spacing of the diodes from the interior of the diffuser minimizes the appearance of point source intensity in the diffuser. It may be desirable in this embodiment to further soften the dispersion of light by use of wide angle light dispersing diodes. The diodes may all be of the same color. The diodes may be electrically connected in patterns of alternating sequential activation to give a flashing, mono-chromatic effect. The diodes may be color coded according to the patterns of alternating sequential activation to give a flashing, color changing effect to the fixture. A translucent color coating can be applied to the exposed exterior display surface of the diffuser to enhance the color of the diodes in monochromatic applications.
The diffuser and housing may be held together by an adhesive bond, or, preferably, by mating channels and flanges extending lengthwise on the diffuser and the housing. Preferably, the housing is sufficiently resiliently flexible to permit the diffuser to be disengaged from and reengaged with the housing so as to permit maintenance of the fixture without removal from its location.
The diodes are preferably fixed to a circuit board and the housing is provided with channels for engagement of the edges of the circuit board to hold the diodes in position in the chamber. In this configuration, the housing is preferably sufficiently resiliently flexible to permit the circuit board to be disengaged from and reengaged with the housing, again to facilitate maintenance without removal of the fixture from its location. Alternatively, interior flanges may be provided on each side of the housing on which the board can be seated, and plastic spring clips used to pin the boards between the flanges and the channels along the housing slot.
This light emitting diode simulation of a neon light affords all of the advantages of LED lighting. It provides a durable, low voltage, low energy, non-gaseous, inexpensive, easy to install, easy to maintain, chromatically versatile, long life fixture which looks like a neon light and demands the attention of the observer.